PAINTSQUARE BLOG

In my previous post, I introduced my concerns about the role of coating condition surveys in keeping offshore workers safe and keeping offshore assets secure. Last week's blog addressed some of the planning that should go into coating condition surveys, as well as the qualifications that a surveyor should possess and the role he or she should play.

In this, the second in this two-part series, we'll take a look at standards that will play a role in many coating condition surveys, and the process itself.

On Visual Standards

A great deal of the coating condition survey is visual in nature, and for this reason, various standards exist for evaluating the extent of corrosion and coating failure. These standards should be used extensively by the coating condition surveyor. It is critical that the use of visual standards, and the type of visual standards to be used, be established at the pre-survey discussions or pre-planning stage.

Coating condition surveys play an important role in keeping offshore workers safe and keeping offshore assets secure.

One such visual standard that is commonly used is the SSPC-VIS2: Standard Method of Evaluating Degree of Rusting on Painted Steel Surfaces (also ASTM D 610).

This standard is regularly used for rust evaluation, and it includes reference color photographs and corresponding black-and-white images that depict the percentage of rusting both in general and pinpoint rusting types.

A table is also included to compare against other rust grade scales, such as the ISO and European grades.

Along with the ASTM D610, ASTM has a number of standards that can be used by the coating surveyor:

ASTM D660 – Degree of checking;

ASTM D661 – Degree of cracking;

ASTM D662 – Degree of erosion;

ASTM D714 – Degree of blistering; and

ASTM D772 – Degree of flaking.

There are clearly a great number of standards available to the surveyor, and the standards to be used for the coating condition survey should be clarified at the pre-planning stage.

While the SSPC and ASTM standards for evaluation are often specified for coating condition surveys in North America, outside of the United States, the international standards are used more frequently. EN ISO 4628 deals with the evaluation of degradation of paint coatings and designation of intensity, quantity and size of common types of defects.

The document, which contains text and black-and-white illustrations, only has six parts:

Part 1 – General principles and rating scheme;

Part 2 – Designation of degree of blistering;

Part 3 – Designation of degree of rusting;

Part 4 – Designation of degree of cracking;

Part 5 – Designation of degree of flaking; and

Part 6 – Designation of degree of chalking.

The coating surveyor can compile a comprehensive report based on the information that the above standards offer, which is comprehensive and technical guidance to the coating condition surveyor to use once in the field.

The Survey Itself

As we are starting to ascertain, there is a great deal of information to be gathered and taken into account in order to execute an efficient and successful coating condition survey, with much pre-planning and many critical points to consider. Once all of the above factors are established, it should be time to move on to the actual coating condition survey.

Typically, a full coating condition survey usually takes the form of non-destructive testing with a high focus on visual assessment for degradation and deterioration of the protective coating, which is to be assessed and compared to the evaluation standards listed above.

The coating condition survey needs to be thoroughly planned, implemented and executed with a pre-determined scope of work that is thoroughly understood by the coating surveyor.

Dry film thickness readings are often required, in addition to a full pictorial reference catalog of the area/equipment being surveyed. However, there is often a requirement to carry out destructive testing, which may include any of the following tests:

Adhesion testing;

DFT assessment using the Paint Inspection Gauge (PIG);

Solvent rub testing; and

Sampling (taking paint flakes for laboratory analysis).

The coating surveyor should also detail at minimum the following items within the coating condition survey report, including the location, zone or area:

Health and safety issues with conducting future work in line with recommendations

There is clearly a great deal of comprehensive pre-planning and coating engineering required in order to implement and execute a successful strategic coating condition survey, and there is an abundance of factors and issues which need to be taken into consideration. It is not a case of simply turning up with a notepad and a camera: The coating condition survey needs to be thoroughly planned, implemented and executed with a pre-determined scope of work that is thoroughly understood by the coating surveyor.

The author would like to thank Brendan Fitzsimons for his technical help and assistance with this piece.

ABOUT THE BLOGGER

Lee Wilson

Lee Wilson, CEng, FICorr, is a NACE Level 3-certified CIP Instructor, NACE Corrosion Specialist, NACE Protective Coating Specialist and Senior Corrosion Technologist, as well as an ICorr Level 3 Painting Inspector and Level 2 Insulation Inspector. The author of the best-selling Paint Inspector’s Field Guide, Lee was named one of JPCL Top Thinkers: The Clive Hare Honors in 2012. Contact Lee.

Thanks Dave I appreciate your comments how are you controlling your RBI and corrosion manageement systems I would be keen to learn of your F&M strategies taking into consideration your vast range of assets!

Comment from Brian Brooker, (9/9/2017, 12:05 AM)

Excellent overview on the proper way to conduct a full coatings survey. Having started out in 1988 performing full coating surveys for Chevron in the Gulf of Mexico until 2004 in Angola Africa on production platforms it was essential to grade the priority of work to be done as well (i.e., priority 1, 2, 3 or 4+) this was based on criteria provided to us by our Chevron Corrosion Mangers. Prioritizing work involved not only most everything your overview stated including rust grades, percentage of corrosion present, production equipment or structural steel and how long will the facility continue to produce. As you stated it takes a experienced and detailed professional to conduct a proper full coatings survey.

For unlimited access to all free content on our site, take 2 minutes to register now. You’ll have a wealth of searchable resources at your fingertips, including news, technical articles, videos, webinars, problem-solving forums and much more.

PLUS: You can sign up for a FREE 3-month trial subscription to the Journal of Protective Coatings & Linings, the voice of SSPC.